<i>Design Goals: ~10^6 to 10^7 machines, ~10^13 directories, ~10^18 bytes of storage (that's 888 petabytes), spread at 100s to 100s of location around the world, ~10^9 client machines.</i><p>Simply staggering. I guess now we also have a formal definition of "Google Scale" which the Google PR people always go on about.
Jeff Dean is like a god around here. Fact: Jeff Dean was forced to invent asynchronous APIs one day when he optimized a function so that it returned before it was invoked. Also, gcc -O4 sends your code directly to Jeff Dean for a rewrite.